Dildo is a toy, penis is a challenge?

For those who like being penetrated, what's the difference between a real penis and a dildo?

I talk mostly about size; I think that, when it comes to a man, every woman if could ever choose his size, would opt for no less than 7", even if she's not particularly into big sizes.
When she has to buy a dildo, she'll choose something more around 6".

In general, the size preference in women seems to expect at least one extra inch in a man wrt the standard dildo.

For what I've seen, women react to a big penis as considering it a 'challenge', so often they look for men hung to the point of causing pain and then they push themselves to accommodate it all.
With dildos the reaction is by far less intense; they can enjoy the stretching feel, but the pain given by the extra size introduces no real pleasure.

It is true that I prefer a slightly smaller dildo to a penis. But larger than the size you quoted. My fav size for dildo is 7" favorite for Penis is > 7". But pain and/or challenge has nothing to do with it! A dildo is just a dildo. Fun in a pinch but does not come close to how good a real cock feels. I think the thrusting action has something to do with it as well. Similar but not the same. A smaller dildo is easier for my small hands to manuever. Also, no matter how much lube I use I can never get as wet for a dildo as I can for a man.
Although for some folks pain may bring them pleasure, I'm not one of them. A big dick just feels way better than a dildo. Just one woman's opinion.